Methods: 30 patients with an open tibial fracture admitted to Songklanagarind hospital from September 2007 to June 2008 and treated by emergency debridement and external fixation were randomized into two groups, one treated with silversulfadiazine for infection prophylaxis (15) and a control group treated with dry dressing only (15). All patients were followed until the external fixator was removed. Pin-site infections were assessed and graded at each follow-up visit by an orthopaedist blinded to the mode of treatment. A culture from the pin site was done if an infection occurred.